Southeastern Section–55th Annual Meeting (23–24 March 2006)
Paper No. 5-4
Presentation Time: 9:10 AM-9:30 AM


ROWAN, E.L.1, RYDER, R.T.1, and REPETSKI, J.E.2, (1) U.S. Geological Survey, 12201 Sunrise Valley Dr., M.S. 956, Reston, VA 20192,, (2) U.S. Geological Survey, 12201 Sunrise Valley Dr., M.S. 926A, Reston, VA 20192

Three regional-scale, 2D cross-sectional burial and thermal history models have been constructed for the undeformed north-central Appalachian basin. The models integrate thermal and geologic data to provide a geologically constrained burial history. The sections extend from the Allegheny structural front in West Virginia and Pennsylvania northwestward across the Rome trough and Dunkard basin and terminate to the northwest near the crest of the Findlay Arch in Ohio. The Dunkard is a ‘sub-basin' within the larger Appalachian basin and a late Paleozoic depocenter with present day depths to basement approaching 30,000 ft.

The models incorporate sedimentation, compaction, uplift, and erosion, and they assume a basement heat flow of 52 mW/m2. Well logs were used to identify and quantify lithologies. Relatively low thermal conductivities were assigned to Pennsylvanian coals (0.2 W/mºC) and Devonian kerogen-rich shales (0.9–1.2 W/mºC) based on published values from the region. Corrected bottom hole temperatures and measurements of conodont color alteration index (CAI) and vitrinite reflectance (Ro%) from Ordovician, Devonian, and Pennsylvanian rocks constrain model temperatures and thermal maturities.

To match the measured thermal maturities, the models required deposition of additional sediment, subsequently removed by erosion. We assumed that maximum burial occurred during the Permian (~270 Ma based on recent apatite and zircon fission track studies) with deposition of a wedge of sediment 10,000 – 13,000 ft thick at the southeast end and thinning to the northwest. Published temperatures from fluid inclusions in sphalerite veinlets in Devonian shale at sites deeper in the basin can be readily accounted for by the burial model. In contrast, published fluid inclusion temperatures from the Findlay Arch are significantly higher than predicted by the burial models. However, the results of fluid flow modeling show that westward flow and advective heat transport from deeper in the basin provide a possible explanation for these high temperatures. The burial/thermal history models permit the thermal maturities of individual hydrocarbon source beds to be calculated across the region. The models also provide the regional temperature and pressure framework needed to model hydrocarbon migration.

Southeastern Section–55th Annual Meeting (23–24 March 2006)
General Information for this Meeting
Session No. 5
Burial, Uplift, and Thermal History of the Appalachian Basin
Marriott Hotel: William Blount North
8:00 AM-12:00 PM, Thursday, 23 March 2006

Geological Society of America Abstracts with Programs, Vol. 38, No. 3, p. 10

© Copyright 2006 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.